Cylinder-head for internal combustion engine



Dec. 9, 1958 R. BOUTELEU X CYLINDER-HEAD F OR INTERNAL COMBUSTION ENGINE 7 Filed July 29, 1955 INVENTOR T 6 4S 0 N B m UJ B United States atent CYLINDER-HEAD FOR INTERNAL COMBUSTION ENGINE Ren Bouteleux, Roueu, France Application July 29, 1955, Serial No. 525,309

4 Claims. (Cl. 123-99) This invention relates to a cylinder-head for internal combustion engines, wherein the exhaust and inlet valves are disposed concentrically into each other, i. e. about a common axis.

- According to anessential feature of this invention the exhaust valve is formed at its inner end with an annular flange comprising an outer valve face and an inner valve seat, and has a tubular cylindrical body guided within the cylinder head, the inner space of this valve communicating with an inlet chamber formed in the cylinder head, while the same valve incorporates a hollow stem actuated by a forked rocker, the stem of the inner inlet valve extending through the aforesaid hollow'stem.

According to a subsidiary feature of this invention the inlet chamber comprises at its inlet side a pre-inlet valve actuated by a rocker operatively connected to the rocker of the inlet valve, so that both valves will be actuated synchronously from the same driving member.

In order to afford a clearer understanding of the invention and of the manner in which the same may be carried out in the practice, a preferred embodiment thereof will be described hereafter with reference to the attached drawing forming part of this specification. -In the drawmg:

Figure l is a vertical section of the cylinder head and valve gear mounted thereon;

Figure 2 is an elevation detail view of the inlet and exhaust valve stems, and

Figure 3 is a plane view from above of the detail shown in Fig. 2.

The cylinder head body is designated by the reference numeral 1. It comprises internally an exhaust chamber 2 with an outlet 3 for the burnt gases and an inlet chamher 4 having a cylinder-forming extension 5 in which is slidably mounted a pre-compression piston 6 the rod 7 of which is operatively connected to any suitable driving mechanism.

Between the exhaust chamber 2 and the inlet chamber 4, the cylinder head has a cylindrical bore 8 in coaxial alignment with the pair of valves. On the engine cylinder side the cylinder head is formed with a compression chamher 9 constituting the bottom of the combustion chamber; between the exhaust chamber 2 and the compression chamber 9 the cylinder head is formed with an annular seat 10 adapted to be engaged by the valve face formed on the lower flange 11 of theexhaust valve of 'which the tubular cylindrical body 12 is slidably guided in the bore 8. At its upper end the exhaust valve is formed with a hollow stem 13 extending through the top of the cylinder head; lateral apertures 14 are provided in the wall of the tubular valve which is located between the tubular cylindrical body 12 and the hollow stem 13, these apertures being level with the inlet chamber 4. The lower flange 11 is formed with an inner annular seat 15 adapted to be engaged by the valve face formed on the head 16 of an inlet poppet valve the stem 17 of which extends through the axial bore formed in the hollow stem 13 of the outer valve.

2,863,429 itatented Dec. 9,""19 58 The cylinder head portion in Whieh'the inlet chamber 4 is formed has an inlet pipe 18 connectedtheretowhich is formed with an annular valve seat 19 adapted to be engaged by the valve face 20 of a pre-inlet valve the stem 21 of which extends acrossthe wall of the inlet pipe 18 to the outside.

The cylinder head is also formed with a cavity 22 adapted to receive the ignition spark plug or a fuel injection nozzle shown in dotted lines at 23. It is also formed with passages 24 through which the rocker-actuatingpushrods extend with a substantial clearance, as will be made clear presently.

The hollow stem 13 of the outer exhaust valve carries at its upper end and externally of the cylinder head a valve collar 25 secured by a frusto-conical split cotter 26, avalve spring 27 being interposed between the valve collar 25 and the valve guide 28 through which the valve stem 13 extends as shown. The inner valve stem 17 is also provided with a valve-collar forming plate 29 secured by a frusto-conical split cotter 30, a pair of parallel springs 31 being interposed between the cylinder head and this plate 29, the latter being guided on the other hand by a fixed rod 32carried by the cylinder head and parallel to th'estem 17. The stem 21 carries a valve collar 33 secured by a frusto-conica'l split cotter 34 and valve spring 35 is interposed between the top at the cylinder head and this valve collar 33. It is apparent that the springs 27, 31 and 35 urge the three valves to their closed positions, and that these valves are adapted to be moved to their open positions through valve gears actuated from a camshaft 36. These valve springs are illustrated in the drawing in the'form of coil springs but it will be readily understood by anybody conversant with the art that any other suitable spring forms may be substituted therefor, such as hair-pin springs or torsion bars.

The three rockers through which the valves 11, 16 and 20 controlled by the springs 27, 31 and 35 are actuated are designated by the reference numerals 37, 38 and 39; rockers 37 and 38 are pivoted on a bracket 40 and the other rocker 39 is pivoted on another bracket 41.

The rocker 37 engages a washer 49 bearing upon the upper end of the exhaust valve and to this end the washer-engaging portion 42 of the rocker is of fork shape so thatthe prongs thereof are located on either side of the stem 17. At its opposite endthe rocker is actuated by a push-rod 43 extending through the aforesaid passage 24; this push-rod is controlled in turn by one of the cams formed on the camshaft 36, a suitable cam follower being interposed therebetween.

The rocker 33 engages the valve stem 17 through a projection or lug 44 and comprises an extension carrying atransverse pin 45 engaging an elongated aperture 46 formed in the other ro'cker 39; this rocker 39 isadapted in turn to actuate the valve stem 21 through an adjustable stud 47. This operative connection between the pair of rockers 38, 39 permits the simultaneous actuation thereof from a common push-rod48 actuated in turn fromaproper cam formed on the camshaft 36.

*One or more piston packings 51 may be provided in the outer cylindrical surface of the bore 8 to ensure a sealing engagement between the exhaust c hamber2 and inletchamber 4. A pipe 52 carrying a suitable nozzle and fed with valve-gear lubricating oil may be provided for supplying lubricant to the bore 8 around the annular valve.

The above-described arrangement operates as follows;

When the induction stroke is to take place the rockers 38, 39 are actuated and open the inlet and pre-inletvalves so that the air or the fuel mixture contained in the inlet chamber is forcedinto the combustion chamber while fresh gas enters the inlet chamber; the filling of the engine cylinder may be improved by compressing beforehand the gas introduced into chamber 4 by causing a proper movement of piston 6 which may be actuated through any suitable mechanism.

After closing the inlet and pre-inlet valves, the engine cycle continues according to the usual sequence, i. e. the compression stroke followed by the explosion or power stroke, whereafter the exhaust valve opens and carries along the inlet valve. The burnt gases escape between the flange 11 of the exhaust valve and the valve seat. across chamber 2 so that only a small percentage of the heat contents of these gases is transferred to the body 12 of the exhaust valve in which the fresh gases issuing from the inlet chamber are now circulating; thus, these fresh inlet gases are pre-heated so as to promote the fuel vaporization and increase the pressure in chamber 4; at the same time, the heat absorbed by the fresh gases will cool the exhaust valve and consequently this valve cannot attain an excessive value. At the end of the exhaust stroke another quantity of fuel mixture is introduced and the cycle is repeated.

Of course, the gases could follow a path exactly opposite to the one just described, without impairing the operation of the cylinder head. The fresh gas inlet would then occur through the chamber 2 and orifice 3 and the burnt gases would escape through the pipe 18 in a direction opposite to that indicated by the arrow in Fig. l.

The device described hereinabove is particularly suitable for slow-running engines employing fuel oil (compression-ignition engines); in fact, these relatively slowrunning engines Will not suffer from the use of exhaust valves slightly heavier than those of ordinary or gasoline engines, and on the other hand the advantages of an improved combustion and a more complete filling of the combustion chamber will appear more obviously in fueloil engines; it is known that these engines have a relatively poor efiiciency with hitherto known or conventional cylinder heads.

Of course, the form of embodiment shown and described herein is given by way of example only and should not be construed as limiting the scope of the invention, as many constructional details may be altered therein without departing from the spirit and scope of the invention. Thus, more particularly, the common axis of the inlet and exhaust valves, instead of being in axial alignment with the combustion chamber, as illustrated, may be inclined in relation thereto to provide a convenient location for the spark plug or fuel injector in the combustion chamber; i. e. at a greater distance from the exhaust valve. Again, the cylinder head may be constructed without the pre-inl'et valve 18 and/or the precompression piston 6; these two mechanisms may also be provided, if desired, on a separate member secured on the cylinder head.

Experience has proved that a cylinder head according to this invention will improve the engine output to a substantial extent, with the additional advantageous feature that the valve heads and their respective seats may withstand extremely long service periods while retaining perfect operative conditions, so that maintenance costs are reduced proportionally.

This invention is also applicable to gasoline and diesel engines of the types employed in fixed installations, in marine and aircraft construction, and in the automotive industry.

I claim:

1. A cylinder head for internal combustion engines, comprising a cylinder head having a chambertherein, a partition connected to said head and extending within said chamber forming an exhaust chamber and an inlet chamber, a cylinder extension connected to said inlet chamber, an inlet pipe leading into said inlet chamber, said head and said partition having concentric bores, a tubular valve slidably mounted through said bores and having a flange for being seated against one side of said head closing said bores, a poppet valve slidably extending through said tubular valve with the head of said poppet valve seatable against said valve flange closing said tubular valve, said tubular valve having openings capable of being in communication with one of said chambers, a pie-compression piston slidably and tightly mounted in said cylinder extension, a pre-inlet valve being slidably mounted in said head and adapted to close said inlet pipe, a plurality of resilient means tending to independently urged said valves in their closed position, a driven camshaft, a plurality of push-rods operable by said camshaft, a plurality of rocker arms pivotally mounted on said head for being pivoted by said push-rods and for sliding and opening said valves, and synchronizing means for operating said pre-inlet valve in proper time with respect to said poppet valve.

2. A cylinder head for internal combustion engines comprising a cylinder head having a chamber therein, a partition connected to said head and extending within said chamber forming an exhaust chamber and an inlet chamber therein, a cylinder extension connected to said inlet chamber, an inlet pipe leading into said inlet chamber, said head and said partition having concentric bores; a tubular valve in one piece slidably mounted through said bores and having a flange for being seated against one side of said head closing said bores, said tubular valve having a tubular portion of reduced diameter, a poppet valve slidably extending through said tubular valve and guided by said tubular portion of reduced diameter of said tubular valve with the head of said poppet valve seatable only against said valve flange closing said tubular valve, said tubular valve having openings capable of being in communication with said inlet chamber, a pre-cornpression piston manually positioned slidably and tightly mounted in said cylinder extension, a pre-inlet valve being slidably mounted in said head and adapted to close said inlet pipe, a plurality of resilient means tending to urge independently said valves in their closed position, a timing arrangement for actuation of said tubular and said poppet valves and synchronizing means for operating said pre-inlet valve in proper time with respect to said poppet valve.

3. A cylinder head for internal combustion engines comprising a cylinder head having a chamber therein, a partition connected to said head and extending within saidchamber forming an exhaust chamber and an inlet chamber therein, said head and partition having concentric bores, a tubular valve slidably mounted through said bores and having a flange for being seated against one side of said head closing said bores, a poppet valve slidably extending through said tubular valve with the head of said poppet valve seatable against said valve flange closing said tubular valve, said tubular valve having side openings capable of being in communication with one of said chambers, a plurality of resilient means tending to retain said valves in their closed position, a driven camshaft, a plurality of push-rods operable by said camshaft, a plurality of rocker arms pivotally mounted on said head each contacting one push-rod for being pivoted thereby and one of said valves for sliding and opening the same, a plurality of plates each being connected to one of said valves, said resilient means being positioned between said plates and said head tending to move said plates from said head and a guide pin being mounted on said head with the plate for said poppet valve being slidable on and guided by said pin,

4. A cylinder head for internal combustion engines as,

claimed in claim 2 wherein said pre-inlet valve has its head positioned for being seated for closing said. pipe from said inlet chamber, resilient means tend to hold said pre-inlet valve in its closed position, a rocker arm is pivotally mounted on said cylinder head for sliding said preinlet valve from its closed position and means connects References (Zited in the file of this patent UNITED STATES PATENTS Edwards Feb. 4, 1908 Krebs Mar. 5, 1912 6 Redrup Apr. 15, 1913 Brown July 18, 1916 Sims July 3, 1917 Asbury May 6, 1924 Zahodiakin Mar. 13, 1934 Price et a1. Feb. 8, 1938 Lothrop Aug. 23, 1938 Brumby Dec. 1, 1942 

